Harvesting mechanism for automatic ice maker

ABSTRACT

The automatic ice maker mold is rotated in a first rotational direction from an inverted to an upright position by a motor driven cam gear having a spiral cam thereon engaging the resiliently flexible cam follower leaf member portion of a pivoted spring biased sector gear whereby the leaf member acts in resilient opposition to the rotation of the cam gear to rotate the mold from an inverted to an upright position and thereafter retaining the mold during water filling and freezing cycles. The ice harvesting cycle commences by reenergization of the motor to continue the rotation of the cam gear until the flexible leaf member drops-off the high portion of the spiral cam releasing the spring biased sector gear to transmit a driving force to the mold in a second rotational direction causing a sudden inverting and impacting of the mold against stop means to dislodge the ice pieces therefrom into an ice collection bin.

ilnited States Patent H91 [111 3,745,779 Bright 1 July 17,1973

[ HARVESTING MECHANISM FOR AUTOMATIC ICE MAKER Primary ExaminerWilliam E. Wayner et a1.

Attorney-William S. Pettigrewfiidward P. Barthel [57] ABSTRACT The automatic ice maker mold is rotated in a first rotational direction from an inverted to an upright position by a motor driven cam gear having a spiral cam thereon engaging the resiliently flexible cam follower leaf member portion of a pivoted spring biased sector gear whereby the leaf member acts in resilient opposition to the rotation of the cam gear to rotate the mold from an inverted to an upright position and thereafter retaining the mold during water filling and freezing cycles. The ice harvesting cycle commences by reenergization of the motor to continue the rotation of the cam gear until the flexible leaf member drops-off the high portion of the spiral cam releasing the spring biased sector gear to transmit a driving force to the mold in a second rotational direction causing a sudden inverting and impactpieces therefrom into an ice collection bin.

3 Claims, 6 Drawing Figures PAIENIEDM 1 1w smears HARVESTING MECHANISM FOR AUTOMATIC ICE MAKER This invention relates to an automatic ice maker and more particularly to an apparatus for automatically harvesting ice masses for use in a household refrigerator.

Prior art icemakers exemplified by the automatic freezer described in U.S. Pat. No. 3,540,227 issued Nov. 17, 1970 to Eyman Jr., et al. and assigned to the same assignee as the instant application discloses a mechanism for automatically filling, freezing and harvesting ice pieces. The harvesting cycle includes an initial twisting of the flexible mold to dislodge the ice pieces. To further insure the complete ejection of all the frozen liquid from the mold a second twisting is imparted to the mold whereupon the mold is suddenly released under the resilient force provided by the twist to accelerate the tray into engagement with a stop. This imparts a jar and the resulting vibration forces eject any remaining frozen liquid from the mold. While the patented automatic ice maker has proved successful the object of the present invention is to provide an improved ejection system wherein the harvesting of ice pieces is accomplished by a sudden 180 rotation of the mold and impacting the mold against a stop such that the impact alone provides a more effective and reliable dislodgement of the ice pieces.

An object of the present invention is to provide an automatic ice maker mechanism for harvesting the ice pieces from a mold wherein the mold is rotated substantially 180 from an inverted position to an upright position for successive water fill'and freeze cycles by means of motive means rotating a gear having a spiral cam on one face thereof in a first direction such that a sector gear resiliently biased in a second direction has a resiliently flexible cam follower leaf member engaged by the spiral cam which acts in resilient opposition to the rotation of the spiral cam thereby rotating the mold in the first direction from an inverted to an upright position and retaining the same during its fill and freezing cyclei, whereupon re-energization of the motor initiates a harvest cycle by causing further rotation of the cam gear'until the flexible leaf member drops-off the high portion of the spiral cam releasing the sector gear resulting in a sudden rotation of the mold in the second direction impacting the mold against stop means to dislodge the ice pieces therefrom solely by jarring the mold as a result of the impact.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIG. 1 is an irregular vertical sectional view through a refrigerator embodying an air cooled automatic freezer illustrating one form of the invention.

FIG. 2 is a vertical sectional view through the automatic freezer shown in FIG. 1.

FIG. 3 is an enlarged vertical sectional view taken along the lines 3-3 of FIG. 4 showing the drive and control mechanism.

FIG. 4 is a sectional view taken along the lines 4----4 of FIG. 3.

FIG. 5 is an irregular horizontal sectional view taken along the lines 55 of FIG. 3 showing the mold in its upright position during its fill and freezing cycles.

FIG. 6 is a view similar to FIG. 5 showing the mold in its inverted harvesting position.

Referring now to the drawings and more particularly to FIG. 1, there is shown the upper portion of a frostfree household refrigerator 20 with an upper belowfreezing compartment 22 closed by an insulated door 24 and a lower above-freezing compartment 26 closed by a lower insulated door 28. These compartments are surrounded by the insulated side,.top, bottom and rear walls 30, separated by a horizontal insulated wall 32 containing an evaporator compartment 34 provided with a finned evaporator 36 having vertical fins extending from the front to the rear of the compartment 34. The evaporator compartment 34 is provided with an inlet 38 at the front communicating with the front of the below freezing compartment 22 and additional inlets (not shown) communicating with the top of the below-freezing compartment 26. At the rear, the compartment 34 connects with a shroud 40 communicating with an entrance to a centrifugal fan 42 which is driven by an electric motor 44 housed in the rear wall 30 of the cabinet. The cooling arrangement for the compartments may be similar to that shown in U.S. Pat. Nos. 3,359,750 issued Dec. 26, 1967, or 3,310,957 issued Mar. 28, 1967 which may be referred to for details of construction of the refrigerator.

The fan 42 is provided with an upwardly extending discharge duct 46 having distributor 48 at the top which distributes the discharge of air through the below-freezing compartment 22. The evaporator 36 is maintained at suitable below-freezing temperatures such as 5 to -l5 F. to maintain the compartment 22 at the temperature of 0 F. or below.

For providing special cooling for the automatic freezer, the distributor 48 is provided with a laterally extending discharge duct 50 extending along the intersection of the rear and top walls. Behind liquid freezer 52 the laterally extending duct 50 is provided with wide discharge nozzle 54 which discharges cold air directly onto the top of the liquid freezer 52 and particularly onto the top of mold 56.

As seen in FIGS. 2 and 5 the mold 56 is provided with two rows of pockets 58 containing four pockets in each row and has upwardly flanged longitudinal rim 60 extending around the short and long sides thereof. The mold 56 of the liquid freezer is supplied with water or any other liquid to be frozen from a pressure water system or other liquid under pressure to a solenoid control valve 62 which controls the water through a pipe 64, extending through the insulation of the top wall to a suitable discharge device 66 in the top wall of the belowfreezing compartment 22 above the front pockets 58 of the mold 56. The freezer 52 is provided with a wide U-shaped frame 68 which surrounds the mold 56 and is fastened to the adjacent side wall of the freezing compartment 22 by suitable screws. Below the frame 68 is a rectangular'bin carrier 70 having, adjacent the rear, upwardly extending pivoting projection 72 pivoted on the pivot pin 74 to the side walls of the frame 68. The bin carrier 70 is provided with supporting ledges 76 on its inner sides for supporting the laterally extending flanges 80 of the box-shaped bin 78. The bin 78 is provided with a double flange 82 at the front to serve as a handle.

At the rear, the mold 56 has an integrally molded boss 84 provided with a recess integrally receiving the flattened cylindrical portion 86 and a coaxial projecting pin 88 of the pivot pin 90 having a bearing portion 92 of reduced size fitting a bearing aperture within the rear wall of the frame 68. The frame 68 has a pair of front and rear stop members 94 and 95 which are lanced and bent inwardly from the frame side wall so as to extend normal thereto into the path of movement of the adjacent front and rear underside portions of the mold rim 60 to stop the mold in its horizontal upright position on the stop upper edges 97 (FIG. As seen in FIG. 6 the stop lower edges 98 engage the forward upper portion of rim 60 while the rear stop (not shown) engages the rearward upper portion of rim 60 when the mold 56 is rotated into its upright horizontal position and thereby limit the travel of the mold to substantially 180.

For accessibility all the mechanism and controls are located at the front of the freezer with the mold rotating an impacting mechanism and the control system being located in the housing 127 while the electric driving motor 129 and the wiring are located in the front face of wall 133. Both the wall 133 and the housings 127 are formed of suitable plastic material. Substantially the entire operating and control mechanism are mounted upon the plastic upright cover or wall 133 which closes the housing 127 to form a compartment 135. The front face of wall 133 has affixed thereto, such as by screws 137, a drive motor 129 having its final drive shaft 138 extending through the dividing wall 133 and provided with a drive pinion 139 on the opposite side which continually meshes with large driven cam or commutator gear 141. The cam gear 141 has an apertured hub 191 (FIG. 4) rotatably mounted in a removable manner by a suitable snap retainer (not shown) on the inner shaft end of hexagon collar bolt 143. The outer threaded end of bolt 143 extends through opening 144 in boss 145 on the wall 133 and is fixedly secured thereto by lock nut 147 and its collar 148.

The cam gear 141 is preferably molded of polycarbonate plastic or the like and has on its inner face integrally molded cam means 150 extending inwardly toward the mold 56. As seen in FIG. 6 the cam means is preferably in the form of a modified Archimedes spiral whose center coincides with the center of the cam gear and extends through an angle X of approximately 255 from its leading or initial edge 151 to a point indicated by line 149, and thence through circular arc Z of about 60, its trailing edge 152 providing a drop-oft gap indicated by angle Y of approximately 45. Thus the spiral cam 150 outer surface 153 becomes progressively greater in radial extent from its initial edge 151 through angle X while remaining at a constant radial distance through angle Z to its trailing edge 152 for a reason to be explained.

As seen in FIGS. 2 and 5 a sector gear 160 is pivotably mounted on the rear wall 127 by means of a pivot stud 161. The segment gear is C-shaped in configuration having an arcuate leg 160a and a radial leg 16012 forming an inner semi-cylindrical surface 1600 with the stud 161 pivoting the segmental gear about its foot portion 162. The sector gear has gear teeth 160d on its arcuate leg 160a extending through an arc of about 33 and is biased into engagement with spiral cam 150 by spring biasing means in the form of a spiral tension spring 164 which has one end secured by means of bracket 165 to the bottom flange of the housing and a loop or hook at the end of spring 164 extends through the bracket 165. The opposite end of spring 164 is secured by a hook being engaged around a pin l60e extending through the slotted free end l60f of the sector gear 160 to normally bias the sector gear 160 in a first rotational direction which in the preferred form (FIG. 6) is a clockwise rotational direction.

As seen in FIG. 5 the gear teeth 160d adjacent the pin securing end l60e of the tooth segment 162 are in mesh with the teeth of pinion gear 167 assuring that the mold is held in upright horizontal position during the water fill cycle. The sector gear contains just enough teeth 160d to cause pinion gear 167 to make one-half of a revolution when the sector gear 160 is rotated approximately 275 to its upward counterclockwise position by cam in a manner to be described. As seen in FIG. 6 the segmental gear has a resiliently flexible cam follower leaf member g of longitudinal extent and being supported solely at one end such as by machine screw 160k and is free to extend lengthwise in a rcsiliently non-flexed condition into a cam gap 160i defined by the cam leading edge 151 and the trailing edge 152. The flexible cam follower leaf member 160g is biased into engagement with the cam member 150 so as to be in resilient opposition to rotation of the cam gear 141. By this arrangement the mold 56 is rotated by the unidirectional drive mechanism 129 to its upright water fill cycle position shown in FIG. 5 with leaf member 160g loaded to its maximum by engagement at the terminus 149 of the spiral arc X.

In considering the operation of the invention it will first be assumed that cam gear 141 is in its water fill cycle position with the mold 56 in its upright position. This is achieved by clockwise rotational movement of the cam gear 141 and spiral cam 150 by the energization of the drive mechanism 129 including pinion 139 in driving relationship with cam gear 141. Upon the leading edge 151 of the spiral cam 150 engaging the underside of flexible leaf member 160b the leaf member is placed in resilient opposition to the rotation of the cam 150 thereby continuously urging the leaf member against the outer cam surface 153 until the progressively higher surface overcomes the biasing effect of the tension spring 164 pivoting the sector gear 160 in a counterclockwise rotational direction driving the pinion gear 167 and mold into its horizontal position of FIG. 5 wherein mold lip 60 engages the stops 97.

As seen in FIG. 4, the cam member 150 is oriented with respect to the commutator 193 such that the trailing edge portion 152 of the spiral cam is located intermediate the boundaries of fill projection 195. As described and shown in the above-mentioned U.S. Pat. No. 3,298,189 the energization of the fill valve 62 commences and continues as the cam gear 141 and its commutator 193 are rotated clockwise at a rate which is timed by the constant speed of the synchronous drive motor 129. This provides a timed period of engagement of the upper end of spring contact 197 with the commutator fill projection 195 which moves upwardly at a constant speed until the projection 195 moves away from the rounded end of contact 197 to deenergize the solenoid fill valve 62. The drive motor 129, however, continues its operation through the contact of the rounded end of the spring holding contact 267 in engagement with the commutator 193. This spring holding contact 267 engages the commutator 193 at all times except when the notch 269 is oriented below the contact 267 as explained in the U.S. Pat. No.

3,540,227. The clockwise rotation of the cam gear 141 and commutator 193 continues until the delay projection or segment 199 passes beneath the holding spring contact 267 and notch 269 begins to pass beneath contact 267. Further clockwise movement of the cam gear 141 is under the control of the bellows operated double throw thermostatic switch 283 having its sensing tube 284 extending into coaxial cavity 289 in the mold boss 175.

After the water fill is complete the water will be at an above freezing temperature and will warm the bellows thermostat switch 283 thereby establishing an altemative circuit which continues the operation of the drive motor 129 and the rotation of the cam gear 141 when the notch 269 passes beneath the holding contact 267. The delay slot 223 is an open or dead spot in the commutator which prevents continuous operation of the motor 129 in the event no water has entered the mold. The open portion 223 cooperates with the adjacent end of pivoted contact member 225 pivoted on pin 227 whose diametrically opposite arm engages a segment contact member described in U.S. Pat. No. 3,540,227.

The arcuate open portion 223 is laid out in a radius struck beneath the hub 191 by the end of the contact member 225 as it pivots on its pin 227. When this end engages the open portion 223, no current can flow through the contact member 225 to the commutator 193 to stop operation of the motor 129 after the fill period.

As explained in the aforementioned U.S. Pat. No. 3,540,227 the motor 129 will not restart until the thermostat sensing bulb 284 is cooled to a temperature of about 16 F. assuring the liquid in the mold 56 is completely frozen. The thermostatic switch completes'the circuit'from the drive motor to the supply which restarts the drive motor 129 causing continued clockwise rotation of the spiral cam 150 through arc Z without increasing the load on leaf member 1603 and thus preventing any possible distortion of the mold. At the precise time for the harvesting cycle of the ice cubes the leaf member 1603 will be released by being free to drop-off cam trailing edge 152 and move to its extended position in gap 160i of the cam surface 153, suddenly releasing the tension force of the fully extended biasing coil spring 164. The tension spring 164 transmits a driving force to the sector gear 160 causing the mold member 56 to accelerate rapidly in a counterclockwise rotational direction through an angle of about 180 until its motion is suddenly arrested by having the underside of lip 60 impact on the upper edges 97 of the stop members 94 and 95 as shown in FIG. 6. The resulting impacting of the tray will impart a jar and vibration to the mold 56 which acts to free the frozen liquid therefrom causing the ice pieces or cubes to fall by gravity into the bin 52 therebelow.

In this way applicant has achieved an improved harvesting mechanism for an automatic ice maker which materially reduces the amount of torque necessary to drive the mechanism as compared to an ice mold twisting arrangement such as disclosed in the above referenced U.S. Pat. No. 3,540,227, for example. The result is achieved because the energy to flip or invert the mold and impact it against the stop means 94, 95 is stored in the coil spring 164 over the entire ejection cycle (I revolution of the cam gear). For example, it has been determined that the torque required of the motor 129 is reduced from about 100 ounce-inches for the icemaker of U.S. Pat. No. 3,540,227 to about 25 ounce-inches for applicants instant invention.

It will be noted that in its biased position shown in FIG. 6 the sector gear 160 is positioned such that the center of its semi-cylindrical inner surface 160c substantially coincides with the center of the circular cam gear 141 such that the sector gear partially envelops the modified cam surface 153 in a spaced noncontacting manner. In this way when the mold is rapidly accelerated to its inverted position the mold rim will impact against the stops 94 and 95 without the possibility of sector gear contacting the cam surface 153. The construction line 149 denotes the transition point or zone between the first spiral portion and second circular portion of the modified cam surface which engages the leaf member 160g during the water fill and freezing cycles of the icemaker.

While the embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be adopted.

1 claim:

1. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support, means for supplying liquid to said mold, means for freezing liquid in said mold, a drive motor, means for ejecting frozen liquid from said mold, temperature responsive control means for said ejecting means, said ejecting means including a sector gear mounted for pivotal movement on said support, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear, biasing means resiliently biasing said sector gear in a first rotational direction whereby said mold is rotated to an in verted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member supported on said sector gear solely at one end, a cam gear drivingly connected to said drive motor for rotation in the first rotational direction, said cam gear having a spiral cam surface thereon formed with a gap portion between leading and trailing edges of said spiral cam surface, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated to said tray inverted position, said spiral cam surface upon rotation of said cam gear in a second rotational direction adapted to operatively engage said leaf spring cam follower in resilient opposition to the rotation of said cam gear, whereby said sector gear is pivoted in the second direction through an are sufficient to rotate said mold to its upright liquid fill and freeze position, upon completion of the freezing of liquid in said mold said drive motor being energized to continue rotation of said cam gear until said leaf member drops-off the cam surface into said gap portion causing said resilient biasing means to transmit a sudden driving force to said mold for rotating said mold in the second direction substantially to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar the ice pieces loose from said mold and cause the ice pieces to fall from said mold into a storage bin therebelow.

2. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support, means for supplying liquid to said mold, means for freezing liquid in said mold, a drive motor, means for ejecting frozen liquid from said mold, temperature responsive control means for said ejecting means, said ejecting means including a mold driving sector gear mounted for pivotal movement on said support, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear, said sector gear resiliently biased in a first rotational direction whereby said mold is rotated in a second rotational direction to an inverted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member of longitudinal extent supported on said sector gear solely at one end, a cam gear drivingly connected to said drive motor for rotation in the first rotational direction, said cam gear having a modified spiral cam surface thereon formed with a gap portion between leading and trailing edges of said spiral cam, said modified spiral cam surface having its center substantially coinciding with the center of said cam gear, said modified spiral cam surface extending from said leading edge through a first angular portion whereby said modified spiral cam surface becomes progressively greater in radial extent from its center and a second angular portion whereby said modified spiral cam surface remains at a constant radial distance from its center terminating at said trailing edge, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated in said tray inverted position, said modified spiral cam surface upon being rotated by said drive motor in the first rotational direction causing said leading edge to operatively engage said leaf spring cam follower adjacent its free end in resilient opposition to the rotation of said cam gear, said sector gear being pivoted in response to the rotation of said cam gear in a second rotational direction against the biasing action thereon by said biasing means until said leaf spring cam follower moves to a transition zone on said cam surface between said first and second angular portions so as to rotate said mold in the first rotational direction to an upright position for commencement of a water fill cycle and a freeze cycle, means for deenergizing said drive motor for a predetermined interval until completion of the water fill and freeze cycles, means for energizing said drive motor to continue rotation of said cam gear without any additional resilient opposition being imparted to said leaf member by said cam second angular portion until said leaf member suddenly drops-ofi said carn surface trailing edge into said gap portion, said sector gear resilient biasing means being responsive to the release of said leaf member to transmit a sudden driving force to said mold thereby rotating said mold in the second direction substantially 180 to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar all the ice pieces loose from said mold and cause the ice pieces to fall from said mold into a storage bin therebelow.

3. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support and within a freezing compartment, means for supplying liquid to said mold, a drive motor, a cam gear driven by said drive motor, means for freezing liquid in said mold, means for ejecting frozen liquid from said mold, said ejecting means including a mold driving C-shaped sector gear defining an inner semi-cylindrical surface, said C-shaped sector gear forming an arcuate leg and a radial leg, the free end of said radial leg connected for pivotal movement on said support, gear teeth formed in said sector gear arcuate leg through an arc of about 30, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear teeth, spring biasing means connected between said support and the free end of said arcuate leg resiliently biasing said sector gear in a first clockwise direction whereby said mold is rotated in a counterclockwise direction to an inverted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member of longitudinal extent supported on said sector gear solely at one end, said cam gear drivingly connected to said drive motor for rotation in a clockwise direction, said cam gear having a modified spiral cam surface thereon formed on one face thereof with a gap portion between leading and trailing edges of said spiral cam surface, said modified spiral cam surface having its center substantially coinciding with the center of said cam gear, said sector gear when in its biased position having the center of its inner cylindrical surface substantially coinciding with the center of said modified spiral cam such that said sector gear partially envelops said cam surface in a non-contacting manner, said modified spiral cam surface extending from said leading edge through a first angular portion of about 255 whereby said modified spiral cam surface becomes progressively greater in radial distance and a second angular portion of about 60 whereby said modified spiral cam surface remains at a constant radial distance from its center terminating at said trailing edge, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated to said tray inverted position, said modified spiral cam surface upon being rotated by said drive motor in a clockwise direction causing said cam surface leading edge to operatively engage said leaf spring cam follower adjacent its free end in resilient opposition to the rotation of said cam gear, said sector gear being pivoted in response to the rotation of said cam gear in a counterclockwise direction against the biasing action thereon by said biasing means until said leaf spring cam follower moves to a transition zone on said cam surface between said first and second angular portions so as to rotate said mold in clockwise direction to an upright position for commencement of a water fill cycle and a freeze cycle, means for deenergizing said drive motor for a predetermined interval until completion of the water fill and freeze cycles, thermal switch means responsive to the freezing temperature of said frozen liquid energizing said drive motor to continue rotation of said cam gear without any additional resilient opposition being imparted to said leaf member by said cam second angular portion until said leaf member suddenly drops-off said cam surface trailing edge into said gap portion, said sector gear spring biasing means being effective to transmit a sudden driving force to said mold thereby rotating said mold in a counterclockwise direction substantially 180 to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar all the ice pieces loose from said mold pockets and cause the ice pieces to fall from said mold into a storage bin therebelow.

t t i Q i 

1. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support, means for supplying liquid to said mold, means for freezing liquid in said mold, a drive motor, means for ejecting frozen liquid from said mold, temperature responsive control means for said ejecting means, said ejecting means including a sector gear mounted for pivotal movement on said support, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear, biasing means resiliently biasing said sector gear in a first rotational direction whereby said mold is rotated to an inverted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member supported on said sector gear solely at one end, a cam gear drivingly connected to said drive motor for rotation in the first rotational direction, said cam gear having a spiral cam surface thereon formed with a gap portion between leading and trailing edges of said spiral cam surface, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated to said tray inverted position, said spiral cam surface upon rotation of said cam gear in a second rotational direction adapted to operatively engage said leaf spring cam follower in resilient opposition to the rotation of said cam gear, whereby said sector gear is pivoted in the second direction through an arc sufficient to rotate said mold to its upright liquid fill and freeze position, upon completion of the freezing of liquid in said mold said drive motor being energized to continue rotation of said cam gear until said leaf member drops-off the cam surface into said gap portion causing said resilient biasing means to transmit a sudden driving force to said mold for rotating said mold in the second direction substantially 180* to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar the ice pieces loose from said mold and cause the ice pieces to fall from said mold into a storage bin therebelow.
 2. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support, means for supplying liquid to said mold, means for freezing liquid in said mold, a drive motor, means for ejecting frozen liquid from said mold, temperature responsive control means for said ejecting means, said ejecting means including a mold driving sector gear mounted for pivotal movement on said support, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear, said sector gear resiliently biased in a first rotational direction whereby said mold is rotated in a second rotational direction to an inverted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member of longitudinal extent supported on said sector gear solely at one end, a cam gear drivingly connected to said drive motor for rotation in the first rotational direction, said cam gear having a modified spiral cam surface thereon formed with a gap portion between leading and trailing edges of said spiral cam, said modified spiral cam surface having its center substantially coinciding with the center of said cam gear, said modified spiral cam surface extending from said leading edge through a first angular portion whereby said modified spiral cam surface becomes progressively greater in radial extent from its center and a second angular portion whereby said modified spiral cam surface remains at a constant radial distance from its center terminating at said trailing edge, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated in said tray inverted position, said modified spiral cam surface upon being rotated by said drive motor in the first rotational direction causing said leading edGe to operatively engage said leaf spring cam follower adjacent its free end in resilient opposition to the rotation of said cam gear, said sector gear being pivoted in response to the rotation of said cam gear in a second rotational direction against the biasing action thereon by said biasing means until said leaf spring cam follower moves to a transition zone on said cam surface between said first and second angular portions so as to rotate said mold in the first rotational direction to an upright position for commencement of a water fill cycle and a freeze cycle, means for deenergizing said drive motor for a predetermined interval until completion of the water fill and freeze cycles, means for energizing said drive motor to continue rotation of said cam gear without any additional resilient opposition being imparted to said leaf member by said cam second angular portion until said leaf member suddenly drops-off said cam surface trailing edge into said gap portion, said sector gear resilient biasing means being responsive to the release of said leaf member to transmit a sudden driving force to said mold thereby rotating said mold in the second direction substantially 180* to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar all the ice pieces loose from said mold and cause the ice pieces to fall from said mold into a storage bin therebelow.
 3. An automatic liquid freezer including a support for a mold having liquid holding pockets mounted for rotational movement on said support and within a freezing compartment, means for supplying liquid to said mold, a drive motor, a cam gear driven by said drive motor, means for freezing liquid in said mold, means for ejecting frozen liquid from said mold, said ejecting means including a mold driving C-shaped sector gear defining an inner semi-cylindrical surface, said C-shaped sector gear forming an arcuate leg and a radial leg, the free end of said radial leg connected for pivotal movement on said support, gear teeth formed in said sector gear arcuate leg through an arc of about 30*, a pinion gear connected to and co-rotatable with said mold in mesh with said sector gear teeth, spring biasing means connected between said support and the free end of said arcuate leg resiliently biasing said sector gear in a first clockwise direction whereby said mold is rotated in a counterclockwise direction to an inverted position engaged by stop means, said sector gear having a resiliently flexible cam follower leaf member of longitudinal extent supported on said sector gear solely at one end, said cam gear drivingly connected to said drive motor for rotation in a clockwise direction, said cam gear having a modified spiral cam surface thereon formed on one face thereof with a gap portion between leading and trailing edges of said spiral cam surface, said modified spiral cam surface having its center substantially coinciding with the center of said cam gear, said sector gear when in its biased position having the center of its inner cylindrical surface substantially coinciding with the center of said modified spiral cam such that said sector gear partially envelops said cam surface in a non-contacting manner, said modified spiral cam surface extending from said leading edge through a first angular portion of about 255* whereby said modified spiral cam surface becomes progressively greater in radial distance and a second angular portion of about 60* whereby said modified spiral cam surface remains at a constant radial distance from its center terminating at said trailing edge, said leaf member extending into said gap portion in resiliently non-flexed condition when said sector gear is rotated to said tray inverted position, said modified spiral cam surface upon being rotated by said drive motor in a clockwise direction causing said cam surface leading edge to operatively engage said leaf spring cam follower adjacent its free end in resilient opposition to tHe rotation of said cam gear, said sector gear being pivoted in response to the rotation of said cam gear in a counterclockwise direction against the biasing action thereon by said biasing means until said leaf spring cam follower moves to a transition zone on said cam surface between said first and second angular portions so as to rotate said mold in clockwise direction to an upright position for commencement of a water fill cycle and a freeze cycle, means for deenergizing said drive motor for a predetermined interval until completion of the water fill and freeze cycles, thermal switch means responsive to the freezing temperature of said frozen liquid energizing said drive motor to continue rotation of said cam gear without any additional resilient opposition being imparted to said leaf member by said cam second angular portion until said leaf member suddenly drops-off said cam surface trailing edge into said gap portion, said sector gear spring biasing means being effective to transmit a sudden driving force to said mold thereby rotating said mold in a counterclockwise direction substantially 180* to its inverted position resulting in an impact with said stop means of sufficient magnitude to jar all the ice pieces loose from said mold pockets and cause the ice pieces to fall from said mold into a storage bin therebelow. 